Foam headliners for vehicles have previously been described which comprise a wire mesh support sandwiched between two laminated layers of cross-linked ethylene or propylene homopolymer or copolymer foam, one layer being thicker than the other. A composite of a polyvinyl chloride homopolymer or copolymer foam and a decorative solid polyvinyl chloride homopolymer or copolymer film layer is laminated to the thick layer of cross-linked foam.
While headliners of this type have been used, such constructions were not entirely satisfactory--they were found to possess significant operational deficiencies. One such deficiency was the fact that as received from the factory, the interior decorative layer, whether cloth or plastic, had a 1/8, 1/4 or 5/8 inch layer of foam glued to its reverse side, which in turn was glued to the headliner. In time this foam deteriorated and as a consequence, the interior decorative layer tended to come loose and sag downwardly from the roof of the vehicle. Attempts to repair the headliner were frustrated by the fact that the headliner had to be removed from the vehicle and stripped of the decorative layer and foam backing so that a new decorative covering could be applied. Unfortunately, the foam sandwiched wire mesh could not readily be cleaned to present a fresh smooth surface to which a fresh decorative layer could be attached. Instead, if solvents were used to clean off the surface, they softened and dissolved away the foam leaving an unsatisfactory surface for application of a new decorative layer. Attempts to prepare a fresh surface by means of a wire brush likewise failed due to the damage to the foam inflicted by the brush. And when it was attempted to simply glue a new decorative covering on top of the original foam layer, the newly applied adhesive interacted with the original adhesive remaining on the foam surface so that the covering would not stick to the foam. Moreover, the two adhesives formed an unsightly, unworkable mess on the headliner such that the headliner was not reusable.
Subsequently, the large automakers turned to other headliner constructions. One large car maker has utilized an unreinforced cardboard or cardboard-like headliner form or shape to which is bonded on the interior side of the vehicle a foam-backed cloth. Bonding between the foam-backed cloth and the headliner form or shape is effected by means of an adhesive. The resultant headliner is held in place by the interior molding and dome light fixture in the vehicle. However, after a few years the cardboard warps and sags out of shape. Another large car manufacturer has resorted to use of headliners composed of foam-backed cloth adhesively bonded to a form or shape of unreinforced foamed polystyrene as the headliner, this also being held in place by the interior molding and the dome light fixture. But after a few years the foamed polystyrene becomes embrittled and cracks when attempts are made to remove the headliner from the vehicle. Another large car manufacturer uses pressed fiberglass in the fabrication of vehicular headliners both as a reinforcing material and as an insulating material. Unfortunately, after a few years the fiberglass layer comes apart and the liner is no longer usable. Thus while these various approaches are satisfactory the outset, in most cases when deterioration set in the only recourse is to remove and throw away the entire headliner and install a new one.